The easiest way to change the URL is to log into your WP Admin panel (suferreri.wordpress.com/wp-admin), then click Posts > All Posts (or Pages > All Pages, if this item is a page). Find the item in question, then hover over it to show the ‘Quick Edit’ edit, then click that. Once done, you should see options to update the post / page title, and the URL. You can also edit the post, and immediately beneath the post title field you’ll see the post URL (if you click on this it should let you edit it).
I’m back with some questions about my images. I would like to know what is the best way to proceed with uploading them. I now have images of all different sizes in my library but the measurements of the display boxes are a certain size, right? So for example, my slideshow images are shown in a certain size in the slideshow even if the original image is larger (I noticed that it does display the smaller ones in the actual size). What is a good size to upload my images in so they all show up the same in the website? Not only in the slideshow but also in the other places they are shown… And should i modify the sizes before uploading or can I just do this in the editing screen of my wordpress dashboard? I would like to maintain a flow with my images so they all look the same and act the same in the website.